EASY
AS and A Level
IMPORTANT
Earn 100

Find the modal class for x and for y in the following tables.

x 0- 4- 14-20
f 5 9 8

 

y 3-6 7-11 12-20
f 66 80 134

Important Questions on Measures of Central Tendency

EASY
AS and A Level
IMPORTANT
Four classes of continuous data are recorded as 1-7, 8-16, 17-20 and 21-25. The class 1-7 has a frequency of 84 and there is no modal class. Find the total frequency of the other three classes.
EASY
AS and A Level
IMPORTANT

Calculate an estimate of the mean of x and of y given in the following tables.

x 0x<2 2x<4 4x<8 8x<14
f 8 9 11 2
EASY
AS and A Level
IMPORTANT
The mean age of the 16 members of a karate club is 26 years and 3 months. One member leaves the club and the mean age of those remaining is 26 years. Find the age of the member who left the club. Give a reason why your answer might not be very accurate.
EASY
AS and A Level
IMPORTANT

The following table summarises the number of tomatoes produced by the plants in the plots on a farm.

No. tomatoes 20-29 30-49 50-79 80-100
No. plots f 329 413 704 258

The tomatoes are weighed accurately and their mean mass is found to be 156.50 grams. At market they are sold for $3.20 per kilogram and the total revenue is $50350. Find the actual mean number of tomatoes produced per plot.

EASY
AS and A Level
IMPORTANT

All the interior angles of n triangular metal plates, denoted by y°, are measured. State the number of angles measured and write down the value of y¯.

EASY
AS and A Level
IMPORTANT

The total mass of gold extracted from a mine is denoted by Σx, which is measured in grams. Find an expression in x for the total mass in:

carats, given that 1 carat is equivalent to 200 milligrams

EASY
AS and A Level
IMPORTANT

The wind speeds, x miles per hour mph, were measured at a coastal location at midday on 40 consecutive days and are presented in the following table.

Speed x mph 15x<17 17x<20 20x<24 24x<25
No. days f 9 13 14 4

Abel wishes to calculate an estimate of the mean wind speed in kilometres per hour km/h. He knows that a distance of 5 miles is approximately equal to 8 km.

Use the wind speeds in mph to estimate the mean wind speed in km/h.

EASY
AS and A Level
IMPORTANT
t 7 8 9 10 11 12 13
f 4 7 9 14 16 41 9

What feature of the data suggests that t¯ is less than the median? Confirm whether or not this is the case